U.S. patent number 11,248,519 [Application Number 16/754,074] was granted by the patent office on 2022-02-15 for active warm-up system and method.
This patent grant is currently assigned to Dana Canada Corporation. The grantee listed for this patent is DANA CANADA CORPORATION. Invention is credited to Ihab Edward Gerges, Jeffrey O. Sheppard.
United States Patent |
11,248,519 |
Gerges , et al. |
February 15, 2022 |
Active warm-up system and method
Abstract
A vehicle heating/cooling system has first and second fluid
circulation loops for circulating engine coolant and automotive
fluid. A first heat exchanger transfers heat from the coolant to
air for the passenger compartment. A second heat exchanger
transfers heat between the coolant and automotive fluid. A first
valve has first and second inlets for receiving coolant from hot
and cold coolant sources, and an outlet for discharging coolant to
the second heat exchanger. A second valve has an inlet for
receiving coolant from the first coolant source, and an outlet for
discharging coolant to the first inlet of the first valve. The
valve positions change with temperature of the coolant and the
automotive fluid, providing preferential heating of the passenger
compartment during cold start-up of the vehicle. The second heat
exchanger and valves may be provided in a temperature control
module.
Inventors: |
Gerges; Ihab Edward (Oakville,
CA), Sheppard; Jeffrey O. (Milton, CA) |
Applicant: |
Name |
City |
State |
Country |
Type |
DANA CANADA CORPORATION |
Oakville |
N/A |
CA |
|
|
Assignee: |
Dana Canada Corporation
(Oakville, CA)
|
Family
ID: |
65994250 |
Appl.
No.: |
16/754,074 |
Filed: |
October 4, 2018 |
PCT
Filed: |
October 04, 2018 |
PCT No.: |
PCT/CA2018/051251 |
371(c)(1),(2),(4) Date: |
April 06, 2020 |
PCT
Pub. No.: |
WO2019/068192 |
PCT
Pub. Date: |
April 11, 2019 |
Prior Publication Data
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|
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Document
Identifier |
Publication Date |
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US 20200332702 A1 |
Oct 22, 2020 |
|
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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62569389 |
Oct 6, 2017 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
F01M
5/02 (20130101); F01P 3/18 (20130101); B60K
11/02 (20130101); B60H 1/038 (20130101); F28D
9/005 (20130101); B60H 1/03 (20130101); F01P
7/165 (20130101); B60H 1/00314 (20130101); F28F
27/02 (20130101); F28D 2021/0089 (20130101); F01P
2003/187 (20130101); F01P 2025/08 (20130101); F01P
2007/146 (20130101); F01P 2060/045 (20130101); F01P
2060/08 (20130101); F01P 2003/182 (20130101); F01P
2037/02 (20130101); F01P 2007/168 (20130101) |
Current International
Class: |
F01P
7/16 (20060101); F01P 7/14 (20060101); B60H
1/00 (20060101); B60H 1/03 (20060101); F01P
3/18 (20060101); F28D 9/00 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2014138991 |
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Sep 2014 |
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WO |
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2016151040 |
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Sep 2016 |
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WO |
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Primary Examiner: Amick; Jacob M
Assistant Examiner: Brauch; Charles J
Attorney, Agent or Firm: Ridout & Maybee LLP
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This application claims priority to and the benefit of U.S.
Provisional Patent Application No. 62/569,389 filed Oct. 6, 2017,
the contents of which are incorporated herein by reference.
Claims
What is claimed is:
1. A heating and cooling system for a vehicle having an internal
combustion engine, a powertrain component and a passenger
compartment, the system comprising: (a) a first fluid circulation
loop for circulating an engine coolant, wherein the first fluid
circulation loop includes said engine; (b) a second fluid
circulation loop for circulating an automotive fluid for
lubricating said powertrain component, wherein the second fluid
circulation loop includes said powertrain component; (c) a first
heat exchanger located downstream of the engine in said engine
coolant circulation loop, the first heat exchanger being adapted to
receive the engine coolant discharged by the engine and transfer
heat from the engine coolant to an air stream provided to the
passenger compartment; (d) a second heat exchanger fluidly
connected to both the engine coolant circulation loop and the
automotive fluid circulation loop and adapted for transferring heat
between the engine coolant and the automotive fluid; (e) a first
valve provided in the engine coolant circulation loop, the first
valve having a first inlet port for receiving said engine coolant
from a first coolant source in said engine coolant circulation
loop; a second inlet port for receiving said engine coolant from a
second coolant source in said engine coolant circulation loop; and
an outlet port for discharging said engine coolant to the second
heat exchanger; wherein the first valve has a first valve position
in which a flow path through the first inlet port and the outlet
port is open, and a second valve position in which a flow path
through the second inlet port and the outlet port is open; (f) a
second valve provided in the engine coolant circulation loop, the
second valve having an inlet port for receiving said engine coolant
from the first coolant source, and a first outlet port for
discharging said engine coolant to the first inlet port of the
first valve; wherein the second valve has a first valve position in
which a flow path through the inlet port and the first outlet port
is partly or completely closed, and a second valve position in
which the flow path through the inlet port and the first outlet
port is open; wherein the first coolant source is located
intermediate a coolant outlet of the engine through which the
engine coolant is discharged, and an inlet of the first heat
exchanger; wherein the second valve is a three-port valve wherein
said outlet port comprises a first outlet port and said flow path
through the inlet port and the first outlet port is the first flow
path; the second valve further comprising a second outlet port, and
a second flow path through the inlet port and the second outlet
port; wherein, in a first operating state wherein the first and
second valves are in their first valve positions, the first flow
path is partly or completely closed, and the second flow path is
open.
2. The heating and cooling system of claim 1, wherein the second
coolant source is located downstream of a coolant outlet of the
first heat exchanger.
3. The heating and cooling system of claim 1, wherein the engine
coolant from the first coolant source is at a higher temperature
than the engine coolant from the second coolant source.
4. The heating and cooling system of claim 1, wherein the first
valve is actuated from its first valve position to its second valve
position in response to a temperature increase of the automotive
fluid.
5. The heating and cooling system of claim 1, wherein the second
valve is actuated from its first valve position to its second valve
position in response to a temperature increase of the engine
coolant discharged by the engine and received from the first
coolant source.
6. The heating and cooling system of claim 1, wherein the second
valve permits a small, predetermined amount of leakage of engine
coolant therethrough in the first valve position.
7. The heating and cooling system of claim 1, further comprising a
third heat exchanger located downstream of the first heat exchanger
in said engine coolant circulation loop, the third heat exchanger
being adapted to receive the engine coolant discharged by the first
heat exchanger, and wherein the second coolant source is located
downstream of a coolant outlet of the third heat exchanger.
8. The heating and cooling system of claim 7, wherein the third
heat exchanger is a radiator.
9. The heating and cooling system of claim 1, wherein, in the first
operating state at initial cold start-up of the engine, both the
first valve and the second valve are in their first valve
positions, such that a first major portion of the engine coolant
from the first coolant source is directed toward the first heat
exchanger, and a first minor portion of the engine coolant from the
first coolant source flows through a leak path of the second valve,
through the open first inlet port and the outlet port of the first
valve, to transfer heat to the automotive fluid flowing through the
second heat exchanger.
10. The heating and cooling system of claim 9, having a second
operating state during warm-up of the engine, after initial cold
start-up, wherein the first valve is in its first valve position
and the second valve is in its second valve position, such that a
second major portion of the engine coolant from the first coolant
source is directed toward the first heat exchanger, and a second
minor portion of the engine coolant from the first coolant source
flows through the second valve, through the open first inlet port
and the outlet port of the first valve, to transfer heat to the
automotive fluid flowing through the second heat exchanger, wherein
the first major portion is greater than the second major portion,
and the first minor portion is less than the second minor
portion.
11. The heating and cooling system of claim 10, having a third
operating state during normal operation of the engine, after
warm-up, wherein both the first valve and the second valve are in
their second valve positions, such that substantially none of the
engine coolant from the first coolant source enters the first valve
through the first inlet port, and such that the engine coolant from
the second coolant source flows through the first valve, through
the open second inlet port and the outlet port, to extract heat
from the automotive fluid flowing through the second heat
exchanger.
12. The heating and cooling system of claim 11, the engine coolant
circulation loop further comprising a bypass passage for bypassing
the first heat exchanger, the bypass passage having an inlet
located between the engine and the first heat exchanger and an
outlet downstream of the first heat exchanger.
13. The heating and cooling system of claim 12, wherein the inlet
of the bypass passage is located downstream of the first coolant
source such that some or all of the engine coolant directed to the
first heat exchanger in at least the second and third operating
states may bypass the first heat exchanger, depending on the
temperature of the coolant at the first coolant source and/or
heating requirements in the passenger compartment.
14. The heating and cooling system of claim 1, wherein the first
fluid circulation loop comprises a high temperature coolant
circulation loop and a low temperature circulation loop; wherein
the engine and the first heat exchanger are provided in the high
temperature coolant circulation loop; wherein the low temperature
circulation loop includes a low temperature circulation loop in
which a low temperature heat exchanger and one of more low
temperature components are provided; and wherein the second coolant
source is located in the low temperature circulation loop,
downstream of the low temperature heat exchanger and upstream of
the one of more low temperature components.
15. The heating and cooling system of claim 11, wherein the second
outlet port of the second heat exchanger is connected to a first
end of a first bypass conduit which bypasses the first heat
exchanger; the system having a fourth operating state to prioritize
heating of the engine under extreme cold start conditions; wherein,
in the fourth operating state, the second flow path from the inlet
port of the second valve to the second outlet port of the second
valve is completely open to permit a major portion of the coolant
to flow through the first bypass conduit.
16. The heating and cooling system of claim 15, further comprising
a second bypass conduit which bypasses the third heat
exchanger.
17. The heating and cooling system of claim 1, wherein the
powertrain component is a transmission and the automotive fluid is
transmission fluid.
18. A method of heating and/or cooling an automotive fluid in a
vehicle using the heating and cooling system according to claim 11,
comprising: (a) in the first operating state of the system with
both the first and second valves in their first positions, starting
the engine of the vehicle under cold start conditions and
circulating the engine coolant through the engine coolant
circulation loop, and circulating the automotive fluid through the
automotive fluid circulation loop, such that most or all of the
engine coolant from the first coolant source flows through the
first heat exchanger and transfers heat to said air stream provided
to the passenger compartment; (b) as the temperature of the engine
coolant discharged by the engine increases, transitioning the
second valve from its first valve position to its second valve
position and transitioning the system from the first operating
state to the second operating state; (c) in the second operating
state of the system with the first valve in its first operating
position and the second valve in its second operating position,
operating the engine under warm-up conditions and circulating the
engine coolant through the engine coolant circulation loop, and
circulating the automotive fluid through the automotive fluid
circulation loop, such that the engine coolant from the first
coolant source continues to flow through the first heat exchanger
and transfers heat to said air stream provided to the passenger
compartment and/or bypasses the first heat exchanger, and such that
the engine coolant from the first coolant source flows through the
second valve to the first valve, and through the first valve to the
second heat exchanger, and transfers heat to the automotive fluid
flowing through the second heat exchanger; and (d) as the
temperature of the engine coolant discharged by the engine
increases to within a normal operating range, transitioning the
first valve from its first valve position to its second valve
position and transitioning the system from the second operating
state to the third operating state; (e) in the third operating
state of the system with both the first and second valves in their
second operating positions, operating the engine under normal
operating conditions and circulating the engine coolant through the
engine coolant circulation loop, and circulating the automotive
fluid through the automotive fluid circulation loop, such that the
engine coolant from the second coolant source flows through the
first valve to the second heat exchanger, and extracts heat from
the automotive fluid flowing through the second heat exchanger, and
such that the such that the engine coolant from the first coolant
source continues to flow through the first heat exchanger and
transfers heat to said air stream provided to the passenger
compartment, and/or bypasses the first heat exchanger.
Description
TECHNICAL FIELD
The present disclosure relates to active warm-up (AWU) system
configurations for automobiles, which provide warm-up of system
components at cold start conditions without delaying cabin warm-up
or defrost times, and without delaying engine warming. The AWU
systems disclosed herein control the source of a heat exchange
fluid that is delivered to a heat exchanger for transferring heat
to or from an automotive fluid that is also delivered to the heat
exchanger during various start-up conditions while also providing
for cabin warm-up and/or defrost functions.
BACKGROUND
It is well understood in the automobile industry that automobiles
function most efficiently once all fluids are circulating within
the automobile systems at their optimum operating temperatures.
Automotive AWU systems are designed to quickly bring automotive
fluids to optimal operating temperatures at start-up, in particular
at cold start-up conditions. However, some AWU systems rely on
removing heat from the system in an effort to quickly bring fluids
to their optimal operating temperature which has an adverse effect
on cabin warm-up and/or defrost times, and may also delay engine
warming. In cold climate regions where passenger comfort and
defrosting functions at cold start conditions are often considered
a priority for users of the automobile, removing heat from the
system in order to warm automobile fluids at the expense of cabin
warm-up and/or defrost can be problematic. Also, delaying engine
warming may have a negative impact on overall fuel economy.
Some AWU systems attempt to improve warm-up at cold start
conditions without adversely affecting cabin warm-up or defrost
times. However, such systems can be costly and can add to the
complexity of the installation of the system and often favour
either cabin warm-up or fluid warm-up at the expense of the other.
In current economic climates where cost effectiveness and
robustness of systems/components are valued and often considered a
priority, an improved AWU system that aims to decrease the time it
takes for key automobile fluids to reach their optimal operating
temperature without delaying cabin warm-up and/or defrost times is
desirable.
SUMMARY
In accordance with an example embodiment of the present disclosure,
there is provided a heating and cooling system for a vehicle having
an internal combustion engine, a powertrain component and a
passenger compartment, the system comprising: (a) a first fluid
circulation loop for circulating an engine coolant, wherein the
first fluid circulation loop includes said engine; (b) a second
fluid circulation loop for circulating an automotive fluid for
lubricating said powertrain component, wherein the second fluid
circulation loop includes said powertrain component; (c) a first
heat exchanger located downstream of the engine in said engine
coolant circulation loop, the first heat exchanger being adapted to
receive the engine coolant discharged by the engine and transfer
heat from the engine coolant to an air stream provided to the
passenger compartment; (d) a second heat exchanger fluidly
connected to both the engine coolant circulation loop and the
automotive fluid circulation loop and adapted for transferring heat
between the engine coolant and the automotive fluid; (e) a first
valve provided in the engine coolant circulation loop, the first
valve having a first inlet port for receiving said engine coolant
from a first coolant source in said engine coolant circulation
loop; a second inlet port for receiving said engine coolant from a
second coolant source in said engine coolant circulation loop; and
an outlet port for discharging said engine coolant to the second
heat exchanger; wherein the first valve has a first valve position
in which a flow path through the first inlet port and the outlet
port is open, and a second valve position in which a flow path
through the second inlet port and the outlet port is open; (f) a
second valve provided in the engine coolant circulation loop, the
second valve having an inlet port for receiving said engine coolant
from the first coolant source, and a first outlet port for
discharging said engine coolant to the first inlet port of the
first valve; wherein the second valve has a first valve position in
which a flow path through the inlet port and the first outlet port
is partly or completely closed, and a second valve position in
which the flow path through the inlet port and the first outlet
port is open; and wherein the first coolant source is located
intermediate a coolant outlet of the engine through which the
engine coolant is discharged, and an inlet of the first heat
exchanger.
In accordance with another example embodiment of the present
disclosure, there is provided a method of heating and/or cooling an
automotive fluid in a vehicle using the heating and cooling system
as described herein. The method comprises: (a) in the first
operating state of the system with both the first and second valves
in their first positions, starting the engine of the vehicle under
cold start conditions and circulating the engine coolant through
the engine coolant circulation loop, and circulating the automotive
fluid through the automotive fluid circulation loop, such that most
or all of the engine coolant from the first coolant source flows
through the first heat exchanger and transfers heat to said air
stream provided to the passenger compartment; (b) as the
temperature of the engine coolant discharged by the engine
increases, transitioning the second valve from its first valve
position to its second valve position and transitioning the system
from the first operating state to the second operating state; (c)
in the second operating state of the system with the first valve in
its first operating position and the second valve in its second
operating position, operating the engine under warm-up conditions
and circulating the engine coolant through the engine coolant
circulation loop, and circulating the automotive fluid through the
automotive fluid circulation loop, such that the engine coolant
from the first coolant source continues to flow through the first
heat exchanger and transfers heat to said air stream provided to
the passenger compartment and/or bypasses the first heat exchanger,
and such that the engine coolant from the first coolant source
flows through the second valve to the first valve, and through the
first valve to the second heat exchanger, and transfers heat to the
automotive fluid flowing through the second heat exchanger; and (d)
as the temperature of the engine coolant discharged by the engine
increases to within a normal operating range, transitioning the
first valve from its first valve position to its second valve
position and transitioning the system from the second operating
state to the third operating state; (e) in the third operating
state of the system with both the first and second valves in their
second operating positions, operating the engine under normal
operating conditions and circulating the engine coolant through the
engine coolant circulation loop, and circulating the automotive
fluid through the automotive fluid circulation loop, such that the
engine coolant from the second coolant source flows through the
first valve to the second heat exchanger, and extracts heat from
the automotive fluid flowing through the second heat exchanger, and
such that the such that the engine coolant from the first coolant
source continues to flow through the first heat exchanger and
transfers heat to said air stream provided to the passenger
compartment, and/or bypasses the first heat exchanger.
In accordance with another example embodiment of the present
disclosure, there is provided a temperature control module for a
vehicle heating and cooling system, wherein the temperature control
module comprises: (a) a transmission fluid heat exchanger
comprising a stack of core plates defining alternating flow
passages for a coolant and for transmission fluid, the heat
exchanger having inlet and outlet manifolds for the coolant and the
transmission fluid, the manifolds extending throughout the height
of the plate stack, the heat exchanger having a top plate with
apertures in fluid communication with the manifolds, the manifolds
being provided with fittings; (b) a valve assembly comprising a
first thermally actuated valve and a second thermally actuated
valve, the valve assembly comprising: a control chamber of the
first valve being located at a first end of the valve assembly, the
control chamber having an inlet for receiving said transmission
fluid and an outlet which is sealingly connected to the top plate
through an attachment flange, and in fluid communication with a
transmission fluid inlet manifold of the heat exchanger; a main
valve chamber of the first valve having first and second inlet
ports and an outlet port, the outlet port being located at a second
end of the valve assembly, with the outlet port being sealingly
connected to the top plate through an attachment flange, and in
fluid communication with a coolant inlet manifold of the heat
exchanger; a coolant inlet fitting for receiving the coolant from a
second coolant source being sealingly connected to the first valve
at said second inlet port of the main valve chamber; and said
second valve having an inlet port for receiving the coolant from a
first coolant source, and an outlet port which is sealingly
connected to the first valve at said first inlet port of the main
valve chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments of the present disclosure will now be
described, by way of example, with reference to the accompanying
drawings, in which:
FIG. 1 is a schematic diagram showing a heating/cooling system
according to a first embodiment;
FIG. 2 is a schematic diagram showing a portion of the
heating/cooling system of FIG. 1 in a first operating state;
FIG. 2A is a cross-section along line 2A-2A' of FIG. 2;
FIG. 3 is a schematic diagram showing a portion of the
heating/cooling system of FIG. 1 in a second operating state;
FIG. 4 is a schematic diagram showing a portion of the
heating/cooling system of FIG. 1 in a third operating state;
FIG. 5 is a schematic diagram showing a heating/cooling system
according to a second embodiment;
FIG. 6 is a schematic diagram showing a portion of the
heating/cooling system of FIG. 5 in a first operating state;
FIG. 7 is a schematic diagram showing a portion of the
heating/cooling system of FIG. 5 in a second operating state;
FIG. 8 illustrates a temperature control module incorporating a
heat exchanger and a pair of thermally actuated valves;
FIG. 9 is a schematic diagram showing a heating/cooling system
according to a third embodiment;
FIG. 10 is a schematic diagram showing a heating/cooling system
according to a fourth embodiment; and
FIG. 11 is a schematic diagram showing a heating/cooling system
according to a fifth embodiment.
DETAILED DESCRIPTION
The following description relates to various embodiments of a
heating/cooling system 10 for a vehicle 1 powered by an internal
combustion engine 12 and having a passenger compartment 14 and a
powertrain component 30 containing an automotive fluid, such as a
lubricant. For example, the powertrain component 30 may comprise
the vehicle transmission, in which the automotive fluid is
transmission fluid. Alternatively, the powertrain component 30 may
comprise an axle, in which case the automotive fluid is axle fluid.
One or more heat exchange fluids are circulated through the
heating/cooling system for heating and/or cooling various vehicle
components. For example, the heat exchange fluids are selected from
one or more of engine coolant, air, water, and refrigerants.
In the specific embodiments described below, the powertrain
component 30 is the vehicle transmission and the automotive fluid
is therefore transmission fluid. Also, all the embodiments
described below include engine coolant as the heat exchange
fluid.
FIG. 1 schematically shows a heating/cooling system 10 according to
a first embodiment, for a vehicle 1 powered by an internal
combustion engine 12 and having a transmission 30. System 10
includes a first fluid circulation loop 20 (solid lines) through
which engine coolant is circulated, and a second fluid circulation
loop 15 (dashed lines) through which transmission fluid is
circulated. There is no mixing of fluids between the first and
second loops 20, 15. System 10 also includes a third fluid
circulation loop 2 (solid lines) through which air is
circulated.
The engine coolant is circulated through the first loop 20 through
a plurality of coolant conduits, which are labeled 22, 23, 25, 36,
37, 38, 40, 70, and the transmission fluid is circulated through
the second loop 15 through a plurality of transmission fluid
conduits 32, 33 and 34. Air is circulated in system 10, and/or
between system 10 and the atmosphere 4, through air conduits 16,
17, 18 and 19.
System 10 includes a first heat exchanger 26 which is adapted to
receive an incoming air stream through air conduit 16, such as
ambient atmospheric air from atmosphere 4 and/or a re-circulated
air stream from passenger compartment 14 through air conduit 19,
and a liquid stream comprising hot engine coolant discharged from
the engine 12 through coolant conduit 22. The air and the coolant
are passed through the first heat exchanger 26 and heat is
transferred from the coolant to the air. The heated air stream
produced by heat exchanger 26 is then blown into the passenger
compartment 14 as a heated air stream through air conduit 17, to
heat and/or defrost the passenger compartment 14 while the
heat-depleted coolant is discharged from the first heat exchanger
26 through coolant conduit 70. The first heat exchanger 26 is
sometimes referred to herein as a "heater core". As shown in FIG.
1, used air is discharged from passenger compartment 14 as exhaust
air stream through air conduit 18, and is returned to the
atmosphere 4, and/or is re-circulated through air conduit 19 and
returned to the first heat exchanger 26.
System 10 also includes a second heat exchanger 28 which is adapted
to receive the transmission fluid circulating in second loop 15,
and to receive engine coolant circulating in the first loop 20. In
particular, the second heat exchanger 28 is a liquid/liquid heat
exchanger which is adapted to receive transmission fluid discharged
from the transmission 30 through transmission fluid conduits 32 and
33, and to discharge the transmission fluid back toward the
transmission 30 through transmission fluid conduit 34. Second heat
exchanger 28 is also adapted to receive engine coolant through
coolant conduit 36 and to discharge the coolant toward the engine
12 through coolant conduit 37. The coolant and the transmission
fluid are passed through the second heat exchanger 26 and heat is
transferred from the coolant to the transmission fluid, or vice
versa, depending on the operating mode of the system 10. The second
heat exchanger 26 is sometimes referred to herein as transmission
oil warmer (TOW) or transmission oil cooler (TOC).
System 10 also includes a third heat exchanger 24 which receives
engine coolant from the first heat exchanger 26 through coolant
conduit 70, or directly from the engine 12 through bypass coolant
conduit 23. The third heat exchanger 24 cools the coolant and then
discharges it through coolant conduit 25, to engine 12 through
conduit 25, and/or through coolant conduit 40 in the direction of
the second heat exchanger 28. In the illustrated embodiment the
coolant conduit 40 is shown as a branch of conduit 25, although any
arrangement of conduits which permits coolant to flow from the
third heat exchanger 24 to one or both of the engine 12 and the
second heat exchanger 28 is within the scope of the present
disclosure. The third heat exchanger 24 is typically a gas/liquid
heat exchanger such as a fan-cooled radiator and uses ambient air
to remove heat from the coolant.
Depending upon the operating conditions of vehicle 1, system 10
supplies the second heat exchanger 28 with a coolant stream at a
temperature such that heat will either be transferred to or removed
from the transmission fluid flowing through the heat exchanger 28.
More specifically, second heat exchanger 28 can be supplied with
coolant from one or both of a "first coolant source" and a "second
coolant source". The first coolant source comprises a flow of
coolant from a location between the engine 12 and the first heat
exchanger 26, such as coolant conduit 38 which receives engine
coolant directly from the engine 12 and branches off from the
coolant conduit 22 upstream of the first heat exchanger 26. The
second coolant source comprises a flow of coolant from a location
downstream of the first heat exchanger 26, and optionally
downstream of the third heat exchanger 24, such as coolant conduit
40 carrying coolant discharged by the third heat exchanger 24. The
first coolant source is generally considered to be a hot or warm
coolant source, having been heated and discharged by the engine,
while the second coolant source is generally considered a cold or
cool coolant source, having been cooled and discharged by the first
heat exchanger 26 and optionally by the third heat exchanger (or
radiator) 24. In general, under most operating conditions the
temperature of the coolant in conduit 38 is higher than the
temperature of the coolant in conduit 40. Therefore, in the present
description, the coolant in conduit 38 is generally referred to
"hot coolant" while the coolant in conduit 40 is generally referred
to as "cold coolant". However, it will be appreciated that under
certain conditions, such as under cold start conditions, the
coolant in conduits 38, 40 may be neither hot nor cold, and may be
at ambient temperatures at initial start-up of the engine. In the
present embodiment the hot and cold coolant streams both comprise
engine coolant circulating within the same circulation loop 20.
However, as further discussed below, the cold coolant source may
comprise a separate circulation loop containing the same or
different coolant. For example, the cold coolant source may
comprise a refrigerant-cooled fluid circulation loop through which
a chilled coolant is circulated.
The system 10 further comprises a first valve 42 and a second valve
82 for controlling the flow of engine coolant within the system 10,
as now described with reference to FIGS. 1-4. The particular
arrangement of valves 42, 82 shown in FIGS. 1-4 allows for active
warm-up of the transmission fluid at cold start conditions without
delaying cabin warm-up and/or defrosting since most or all of the
coolant discharged by the engine 12 through coolant conduit 22 will
initially flow through the first heat exchanger 26 (heater core for
cabin heating), until the cabin is heated and/or defrosted and/or
the coolant reaches a sufficiently high temperature, as will be
described in further detail below.
The first valve 42 controls the source of the engine coolant
supplied to the second heat exchanger 28, based on the temperature
of a control fluid. First valve 42 is a two-chamber control valve
having a first valve chamber 46 for sensing the temperature of the
control fluid, wherein the control fluid is the transmission fluid
discharged by the transmission 30 through transmission fluid
conduit 32. The first valve chamber 46 is also referred to herein
as the "control chamber". The transmission fluid is continuously
circulated through the first valve chamber 46 throughout all
operating states of the system 10.
The second valve chamber 48 is a three-port valve chamber and
serves to direct coolant from one or both of the first (hot)
coolant source 38 and the second (cold) coolant source 40 to the
second heat exchanger 28 through transmission fluid conduit 36.
Second valve chamber 48 has a first inlet port 50 fluidly coupled
to hot coolant source 38 and a second inlet port 52 fluidly coupled
to the cold coolant source 40. Valve chamber 48 is also provided
with outlet port 54 which is fluidly coupled to the coolant conduit
36 through which the coolant is discharged from the second valve
chamber 48 and delivered to the second heat exchanger 28. First
valve chamber 46 and second valve chamber 48 are fluidly isolated
from each other in that fluid entering/exiting the first valve
chamber 46 does not mix with or come into contact with the fluid
entering/exiting the second valve chamber 48.
As schematically shown in FIGS. 2-4, a thermal actuator 55 is at
least partially disposed within the first valve chamber 46 for
contact with the transmission fluid flowing through the first valve
chamber 46. As is known in the art, the thermal actuator 55
includes an actuator piston movable from a first position to a
second position by means of expansion/contraction of a thermal
modulation device contained in the thermal actuator 55. The thermal
modulation device expands/contracts in response to the temperature
of the transmission fluid flowing through valve chamber 46. While
reference is made to a thermal actuator 55 having a thermal
modulation device in the form of a wax motor, it will be understood
that any suitable thermal actuator incorporating a thermal
modulation device as known in the art may be used.
A valve mechanism 56, such as a valve disk or spool valve
mechanism, is disposed within the second valve chamber 48 for
controlling the flow of the coolant entering the second valve
chamber 48 of first valve 42. The valve mechanism 56 is operatively
coupled to the thermal actuator 55 through the piston and is
moveable from a first valve position to a second valve position
upon actuation by the thermal actuator 55, as further described
below.
Second valve 82 is a two-port thermal mechanical valve which is in
fluid communication with the first coolant source, i.e. the coolant
flowing through hot coolant conduit 38, downstream of the engine 12
and upstream of both the first heat exchanger 26 and the first
valve 42, so as to receive hot coolant from the engine 12 and
control flow of the hot coolant through coolant conduit 38 to the
first valve 42. In schematic FIGS. 1-4 the first and second valves
42, 82 are shown as being physically separated from one another and
from second heat exchanger 28, with second valve 82 being located
in coolant conduit 38 upstream of the first valve 42. However, it
will be appreciated that the valves 42, 82 are not necessarily
physically separated from one another or from second heat exchanger
28, but may be integrated into a single unit or module, as further
discussed below.
The function of the second valve 82 is to delay the drawing of
thermal energy for active warm-up purposes during the initial phase
of cold start-up of engine 12 so as to prioritize cabin heating
over active warm-up, and to prevent the AWU system from delaying
engine warming, which may have a negative impact on overall fuel
economy.
Second valve 82 has a valve chamber 83, an inlet port 84 in fluid
communication with the coolant outlet port of engine 12 and/or the
coolant conduit 22, and an outlet port 86 in fluid communication
with the first inlet port 50 of second valve 42. A thermal actuator
87 is disposed within valve chamber 83, the thermal actuator 87
comprising a thermal modulation device for controlling an actuator
piston and a valve mechanism 88, the valve mechanism 88 moving from
a first, closed position to a second, open position based on the
temperature of the fluid entering valve chamber 83 through inlet
port 84.
The heating/cooling system 10 has three operating states, which are
shown in FIGS. 2, 3 and 4 and now discussed below. In the present
embodiment, it is assumed that the typical temperature range of
transmission fluid in an automobile system is generally in the
range of about -30 to 170.degree. C., with the optimal operating
temperature range being in the range of about 50 to 100.degree.
C.
FIG. 2 shows the positions of valves 42, 82 in a first operating
state of the system 10, also referred to herein as cold start-up.
This operating state exists at initial start-up of engine 12 under
cold conditions. Under these conditions, the passenger compartment
14 may require heating and/or defrosting, and the first operating
state of system 10 is configured to prioritize cabin warm-up and/or
defrost functions in the passenger compartment 14 of vehicle 1.
Under initial cold start-up conditions, both the first valve 42 and
the second valve 82 are in their first valve positions, shown in
FIG. 2.
In the first operating state of system 10, the temperature of the
transmission fluid flowing through the first valve chamber 46 is
low, and may be at or near ambient temperature. Under these
temperature conditions, the thermal modulation device in the
thermal actuator 55 and the actuator piston remain in their
contracted states and the valve mechanism 56 adopts the first valve
position shown in FIG. 2. In the first valve position, valve
mechanism 56 blocks the second inlet port 52, preventing coolant
from entering the second valve chamber 48 through second inlet port
52 and coolant conduit 40 (i.e. from the second or cold coolant
source), while leaving the first inlet port 50 at least partially
open to the second valve chamber 48 through a radial flow passage
80 of valve mechanism 56 (FIG. 2A), such that the second valve
chamber 48 is in fluid communication with coolant conduit 38 (first
or hot coolant source) through the first inlet port 50.
The first position of the second valve 82 corresponds to its closed
position, with the thermal actuator 87 and the actuator piston in
their contracted state and the valve mechanism 88 blocking most or
all of the fluid flow through the valve chamber 83 from inlet port
84 to outlet port 86. For example, in FIG. 2 the valve mechanism 88
is seated on a valve seat. Thus, most or all of the hot coolant
from engine 12 is prevented from flowing through coolant conduit 38
to the first inlet port 50 of first valve 42.
In the first operating state of system 10, with the first and
second valves 42, 82 in their first positions, most or all of the
coolant discharged by engine 12 will flow through coolant line 22
to the first heat exchanger 26 to provide cabin heating and/or
defrosting, and little or no coolant flows through the second heat
exchanger 28 due to the closed first position of second valve 82.
Therefore, in the first operating state, little or no heat is
transferred to the transmission fluid flowing through the second
heat exchanger 28. In this way, the heating/cooling system 10
according to the present embodiment permits cabin warm-up and
defrost functions to be prioritized over active warm-up under cold
start conditions. Typically, the system will remain in the first
operating state during the initial stages of cold start-up, where
the temperature of the coolant discharged by the engine 12 remains
below a low temperature threshold temperature, typically in the
range of about 35.degree. C. to 45.degree. C., for example about
40.degree. C.
In some embodiments, there may be a minor amount of coolant leakage
though the second valve 82 in its first, closed position, and the
second valve 82 may be designed to provide a pre-defined amount of
fluid flow, which may also referred to herein as "leakage" because
it typically represents a minor amount of the total coolant flow
through system 10. For example, as shown in FIGS. 2-4, a leak path
90 may be provided through the valve mechanism 88 of second valve
82. Allowing a small amount of fluid leakage through the closed
second valve 82 will permit a limited amount of hot coolant flow
through coolant conduit 38, into the inlet port 84 of second valve
82, passing through second leak path 90 and through the valve
chamber 83 to the outlet port 86, through conduit 38 and into the
open first inlet port 50 of first valve 42, through the radial flow
passage 80 and through the second valve chamber 48 and outlet port
54, and then through the coolant conduit 36 to second heat
exchanger 28, where the hot coolant transfers heat to the cold
transmission fluid from transmission 30. In this way, limited
leakage of hot coolant through the closed second valve 82 ensures
that cabin heating/defrost functions will be prioritized over AWU,
but the hot coolant will effectively prime the AWU system by
providing a limited amount of transmission fluid warming. Also,
leakage is beneficial where the second valve 82 is thermally
actuated, as it ensures that the thermal actuator 87 will be
maintained in contact with the stream of coolant discharged by the
engine 12. It will be appreciated that leak path 90 may be formed
in various ways, and may comprise one or more bores which define
flow paths through valve mechanism 88.
In operation, the amount of leakage of hot coolant through the
closed second valve 82 will typically be no more than about 10
percent of the maximum coolant flow through coolant conduit 38,
more typically about 5 percent. It will be appreciated that a major
portion of the coolant exiting engine 12 and flowing through
coolant conduit 22 will typically flow to the first heat exchanger
26 under all operating conditions described herein, and a minor
portion of the coolant from engine 12 will be diverted into coolant
conduit 38. The major and minor portions of coolant will vary
somewhat from one application to another. In the first operating
state illustrated in FIG. 2, the volume of flow through the leak
path 90 represents a very small proportion of the total coolant
flow exiting engine 12 through coolant conduit 22. For example, in
the first operating state, the volume of coolant flow from engine
12 to first heat exchanger 26 may represent greater than about 99%
by volume, for example about 99.5% by volume, of the total coolant
flow exiting engine 12 through coolant conduit 22, whereas the
volume of leak flow through leak path 90 in the first operating
state may represent less than about 1% by volume, for example about
0.5% by volume, of the total coolant flow exiting engine 12 through
coolant conduit 22. Therefore, in a typical application, the amount
of hot coolant from engine 12 which reaches second heat exchanger
28 in the first operating state will typically represent less than
about 1% by volume of the total volume of coolant flow exiting
engine 12 through coolant conduit 12, for example about 0.5% by
volume. However, it will be appreciated that the amount of leakage
through second valve 82 may vary from one application to
another.
As the temperature of the coolant discharged by the engine 12
and/or leaking through the second valve 82 increases during the
cold start-up phase, the system 10 will move from the first
operating state to the second operating state shown in FIG. 3, also
referred to herein as warm-up. At the transition between the first
and second operating states of system 10, the temperature of the
coolant circulating through loop 20 increases and the passenger
compartment 14 has been at least partially heated and/or defrosted
by the heated air produced by heat transfer from the coolant in the
first heat exchanger 26, and some limited warming of the
transmission fluid may have taken place due to leakage of coolant
through second valve 82. As the temperature of the coolant reaches
a predetermined low threshold temperature optimized for the
operating condition of the vehicle, for example from about
35.degree. C. to 45.degree. C., for example about 40.degree. C.,
the predetermined low threshold temperature being indicative of a
certain degree of cabin warm-up and/or defrost during the cold
start-up period, the thermal modulation device in the thermal
actuator 87 of second valve 82 expands, causing the actuator piston
to move the valve mechanism 88 from the first valve position to the
second valve position, shown schematically in FIG. 3. As it moves
between the first and second valve positions, the valve mechanism
88 moves away from its first (e.g. seated) position to allow a
greater amount of the coolant discharged by engine 12 to flow
through the valve chamber 83. In the second operating state of
system 10, the first valve 42 remains in its first position, i.e
the same position as in FIG. 1, such that the heated coolant from
the first coolant source, discharged by engine 12 and flowing
through open second valve 82, flows through coolant conduit 38 to
the first inlet port 50 of first valve 42, through the radial flow
passage 80 and second valve chamber 48 of first valve 42, through
the outlet port 54 and coolant conduit 38 to the second heat
exchanger 28, to warm the transmission fluid as it flows through
second heat exchanger 28.
In the second operating state, the coolant discharged by engine 12
is also permitted to flow to the first heat exchanger 26.
Therefore, after the second valve 82 opens, the active warm-up and
cabin heating/defrost functions continue operating as needed, at
least until the vehicle reaches normal operating temperature.
However, because second valve 82 is open in the second operating
state, the volume of coolant flow through coolant conduit 38 and
second valve 82 is greater in the second operating state than in
the first operating state. For example, with the second valve 82 in
the open position as shown in FIG. 3, the volume of coolant flow
from engine 12 to first heat exchanger 26 may represent about
85-90% by volume of the total coolant flow exiting engine 12
through coolant conduit 22, whereas the volume of flow through open
second valve 82 in the second operating state may represent about
10-15% by volume of the total coolant flow exiting engine 12
through coolant conduit 22. Therefore, in a typical application,
the amount of hot coolant from engine 12 which reaches second heat
exchanger 28 in the second operating state will typically represent
about 10-15% by volume of the total volume of coolant flow exiting
engine 12 through coolant conduit 12.
Once the transmission fluid reaches or exceeds its normal operating
temperature, the system 10 will adopt the third operating state
shown in FIG. 4, also referred to herein as normal operation.
Typically the transition from the second operating state to the
third operating state will occur when the transmission fluid
reaches a temperature of about 70-75.degree. C. In the third
operating state of system 10, the first valve 42 will adopt its
second valve position as described below, and the second valve 82
will remain in its second valve position.
As the transmission fluid reaches the normal operating temperature,
the thermal modulation device in the thermal actuator 55 of the
first valve 42 expands, causing the actuator piston to move the
valve mechanism 56 from the first valve position to the second
valve position, shown schematically in FIG. 4. As it moves between
the first and second valve positions, the valve mechanism 56 moves
out of blocking relation with the second inlet port 52 and moves
into blocking relation with the first inlet port 50. Once the valve
mechanism 56 reaches the second position, the second inlet port 52
is open and the first inlet port 50 is closed. Thus, the hot
coolant from the first coolant source flowing through conduit 38 is
prevented from entering second valve chamber 48 through first inlet
port 50, while the cold coolant from the second coolant source
flowing through conduit 40 is permitted to enter the second valve
chamber 48 through second inlet port 52. As in the first valve
position, the coolant is then discharged from second valve chamber
48 through outlet port 54 and enters the coolant conduit 36 leading
to the second heat exchanger 28. The second valve position is a
high temperature configuration which exists once the transmission
fluid reaches or exceeds its normal operating temperature and is
typically at a higher temperature than the cold coolant in conduit
40, which has been cooled in the first heat exchanger 26 and/or the
third heat exchanger (e.g. radiator) 24. Under these conditions,
the coolant will extract heat from the transmission fluid in the
second heat exchanger 28, so as to maintain the temperature of the
coolant within a desired operating temperature range.
The system 10 will typically remain in the third operating state
throughout normal operation of the vehicle 1. Also, during normal
operation, the requirement for cabin heating and/or defrosting may
cease or at least be reduced. Under these conditions, some or all
of the hot coolant discharged by engine 12 may be diverted away
from the first heat exchanger 26 and directed to the third heat
exchanger 24 through a bypass coolant conduit 23. The branch point
between coolant conduit 22 and bypass conduit 23 is located
downstream of the branch point between coolant conduit 22 and
coolant conduit 38, and upstream of the first heat exchanger
26.
The bypass circuit may include a two-port thermal mechanical bypass
valve (not shown) in the bypass conduit 23, similar to the second
valve 82, or a three-port thermally actuated bypass valve (not
shown) at the branch point between coolant conduit 22 and bypass
conduit 23. The bypass valve will have a first, low temperature
configuration in which coolant flow from engine 12 to first heat
exchanger 26 is open and coolant flow through the bypass conduit 23
is partially or completely blocked; and a second, high temperature
configuration in which coolant flow through the bypass conduit 23
is open and coolant flow to first heat exchanger 26 is partially or
completely blocked.
FIGS. 5-7 schematically show a heating/cooling system 100 according
to a second embodiment. System 100 includes a number of elements in
common with system 10 described above. Like elements of systems 10
and 100 are identified with like reference numerals, and the
description of these elements in relation to system 10 applies
equally to system 100, except where noted below.
System 100 differs from system 10 in that the two-port second valve
82 of system 10 is replaced by a three-port second valve 82A which
is positioned at the branch point between coolant conduit 22, which
is the coolant outlet conduit of engine 12, and the coolant conduit
38, which communicates with the first inlet port 50 of first valve
42.
As shown in FIGS. 6 and 7, second valve 82A has an internal valve
chamber 64 formed therein and is provided with an inlet port 66
fluidly coupled to the hot coolant outlet of engine 12 through
coolant conduit 22, a first outlet port 68 fluidly coupled to the
inlet of heat exchanger 26 and the coolant bypass conduit 23
through coolant conduit 22, and a second outlet port 72 which is
fluidly coupled to the first inlet port 50 of first valve 42
through coolant conduit 38.
The second valve 82A may be thermally actuated, having a thermal
actuator 74 and valve mechanism 76 disposed within valve chamber 64
for controlling the flow of fluid through valve 82A. As described
above, the thermal actuator 74 incorporates a thermal modulation
device and an actuator piston for moving the valve mechanism 76
from a first valve position to a second valve position as the
temperature of the fluid flowing through valve chamber 64 (i.e. the
engine coolant exiting the engine 12) increases. As with system 10,
the second valve 82A of system 100 is in the first valve position
when the system 100 is in the first operating state, in which cabin
heating and/or defrosting is prioritized. The first operating state
of system 100 is illustrated in FIG. 6. The second valve 82A is in
its second valve position when the system 100 is in the second and
third operating states. The second operating state of system 100 is
illustrated in FIG. 7.
In the first valve position of second valve 82A, the inlet port 66
is open, the first outlet port 68 is open, and the second outlet
port 72 is partly or completely closed. This first position of
valve 44 forces the engine coolant exiting the engine 12 through
coolant conduit 22 to flow through first heat exchanger 26 while
partly or completely blocking flow through coolant conduit 38 to
the first valve 42. The valve mechanism 76 includes a radial flow
path 77 which may be similar to radial flow path 80 of first valve
42 of system 10. According to this arrangement, a major portion of
the coolant exiting engine 12 through coolant conduit 22 will flow
through the radial flow path 77 of valve mechanism 76 and valve
chamber 64 from inlet port 66 to first outlet port 68.
As with valve mechanism 88 described above, valve mechanism 76 may
include a leak path 78 through which a predetermined amount of
coolant may be discharged from valve chamber 64 through the second
outlet port 72, thereby permitting a minor portion of hot coolant
flow from the engine 12 to enter coolant conduit 38, through the
second valve chamber 48 and radial flow path 80 of first valve 42,
to the second heat exchanger 28, as described above with reference
to system 10. The major and minor amounts of coolant flow in the
first operating state of system 100 may be the same as or similar
those described above in system 10. However, it will be appreciated
that the amount of leakage may vary from one application to
another.
As the temperature of engine coolant exiting engine 12 increases,
the thermal modulation device in the thermal actuator 74 of second
valve 82A expands, causing the actuator piston to move the valve
mechanism 76 from the first valve position to the second valve
position, shown schematically in FIG. 7. In this regard, the valve
mechanism 76 of second valve 82A moves out of blocking relation
with the second outlet port 72, while the inlet port 66 and the
first outlet port 68 remain open. With second valve 82A in the
second valve position, some engine coolant will continue to flow
through the radial flow path 77 of first valve 26, such that a
greater portion of the coolant from the first coolant source in
coolant conduit 22 will be directed by second valve 82A to the
first inlet port 50 of the first valve 42 in the second operating
state, as opposed to the first operating state.
In the second operating state of system 100, the first inlet port
50 of first valve 42 is open, permitting the hot coolant from
conduit 38 to pass through the radial flow path 80 and second valve
chamber 48 of first valve 42 and flow to the second heat exchanger
28 to heat the transmission fluid flowing therethrough. In the
third operating state of system 100, the second valve 82A will
remain in its second valve position while the first valve 42 will
move from its first valve position to its second valve position,
exactly as described above with reference to system 10 and shown in
FIG. 4. In the third operating state, the cold coolant from conduit
40 will pass through the second valve chamber 48 of first valve 42
and flow to the second heat exchanger 28 to extract heat from the
transmission fluid flowing therethrough. As with the first
operating state, the relative volumes of coolant flow to the first
and second heat exchangers 26, 28 in the second and third operating
states of system 100 may be the same as or similar to those
described above in system 10.
FIG. 8 illustrates a temperature control module 150 which may be
incorporated into heating and cooling system 10 described above.
The temperature control module 150 incorporates a heat exchanger
and a pair of thermally actuated valves. More specifically, using
like reference numerals to identify like elements, module 150
incorporates the second heat exchanger 28, the first valve 42 and
the second valve 82.
The second heat exchanger 28 is a transmission fluid heater/cooler
in the form of a plate-type heat exchanger comprising a stack of
core plates 152 defining alternating flow passages for coolant and
transmission fluid in spaces between the plates 152, and having
apertures defining manifolds (not shown) extending throughout the
height of the plate stack. The heat exchanger 28 includes a bottom
plate 154 closing the bottom ends of the manifolds and a top plate
156 having apertures (not shown) in open fluid communication with
the manifolds, the apertures being provided with fittings secured
to the top plate 156. In the illustrated embodiment, the fittings
on top plate 156 comprise: a first valve attachment flange 158 in
fluid communication with the transmission fluid inlet manifold; a
tubular transmission fluid outlet fitting 160 in fluid
communication with a transmission fluid outlet manifold and being
adapted for connection to transmission fluid conduit 34; a second
valve attachment flange 162 in fluid communication with the coolant
inlet manifold; and a tubular coolant outlet fitting 164 in fluid
communication with the coolant outlet manifold and being adapted
for connection to coolant conduit 37.
The first and second valve attachment flanges 158 and 162 are
sealingly secured to a valve assembly 166 incorporating first and
second valves 42, 82. The valve assembly 166 includes a first
attachment flange 168 located at one end of the valve assembly 166,
at which the first valve chamber 46 (i.e. control chamber) of the
first valve 42 is located. The first attachment flange 168 is
adapted to be sealingly secured to the first valve attachment
flange 158 and has an aperture (not shown) which is in fluid
communication with the first valve chamber 46 and with the
transmission fluid inlet manifold through the first valve
attachment flange 158. The valve assembly 166 is further provided
with a tubular transmission fluid inlet fitting 170 which is in
fluid communication with the interior of the first chamber 46, and
which is adapted for connection to transmission fluid conduit
32.
The valve assembly 166 includes a second attachment flange 172
located at another end of the valve assembly 166, at which the
second valve chamber 48 of the first valve 42 is located. The
second attachment flange 172 is adapted to be sealingly secured to
the second valve attachment flange 162 and has an aperture (not
shown) which is the outlet port 54 of the second valve chamber 48
and which is in fluid communication with the coolant inlet manifold
through the second valve attachment flange 162. The valve assembly
166 is further provided with a tubular coolant inlet fitting 174
which is in fluid communication with the interior of the second
valve chamber 48, and which is adapted for connection to (cold)
coolant conduit 40. The tubular coolant inlet fitting 174 defines
the second inlet port 52 of the second valve chamber 48 of first
valve 42.
The valve assembly 166 further comprises second valve 82 which has
one end provided with a tubular hot coolant inlet fitting 176 which
defines the inlet port 84 of second valve 82, and which is in fluid
communication with the valve chamber 83 of valve 82 and coolant
conduit 38. The other end of second valve 82 defines the outlet
port 86 of valve 82, and is directly connected to the valve 82
through a tubular connection which defines the first inlet port 50
of the second valve chamber 48 of first valve 42. The thermal
actuator 87 and valve mechanism 88 of the second valve 82 are not
visible in FIG. 8, however, it will be appreciated that they are
located inside the valve chamber 83 between the opposite ends of
second valve 82. The operation of the temperature control module
150 is in accordance with the operation of system 10, described
above.
Although FIG. 8 describes a temperature control module 166 adapted
for use in system 10, it will be appreciated that a similar module
may be constructed for use in system 100, where the two-port
thermal mechanical valve 82 of system 10 is replaced by three-port
valve 82A of system 100. The structure of such a module could be
similar to the structure of module 166, except that the second
valve 82 depicted therein will have a second outlet between its
ends for diverting the coolant flow to the first heat exchanger
26.
While the first valve 42 of systems 10 and 100 comprises a
two-fluid thermal mechanical valve, it may instead comprise an
electronic valve to achieve similar results. FIG. 9 illustrates a
heating/cooling system 110 according to a third embodiment, wherein
the thermal mechanical three-port first valve 42 of systems 10 and
100 is replaced by a three-port electronically actuated
proportional first valve 42A having an electromechanical actuator
45 such as a solenoid or motor. The valve 42A does not require a
control chamber 46 in which the temperature of the transmission
fluid is sensed by a thermal actuator 55. Rather, in system 110,
the temperature of the transmission fluid within the second fluid
circulation loop 15 is monitored by a transmission fluid
temperature sensor 58, which transmits a signal to an electronic
controller 60, the controller 60 then controlling the actuator 45
which causes displacement of the valve mechanism of valve 42A.
Similar to the first valve 42 of system 10, the first valve 42A is
arranged upstream of second heat exchanger 28 and is controllable
to select between the hot coolant stream from the first coolant
source exiting the engine 12 and flowing through coolant conduit
38, the cold coolant stream from the second coolant source exiting
the first heat exchanger 26 and/or the third heat exchanger 24 and
flowing through coolant conduit 40, or a combination of the hot and
cold streams, depending on the temperature of the transmission
fluid sensed by sensor 58. The coolant stream selected by
electronically actuated first valve 42A is delivered to second heat
exchanger 28 for heat transfer with the transmission fluid flowing
through heat exchanger 28.
FIG. 9 also shows that the two-port thermally actuated second valve
82 of system 10 may be replaced by a two-port electronically
actuated second valve 82B having an electromechanical actuator 61
such as a solenoid or motor, instead of thermal actuator 87. Second
valve 82B has a valve mechanism which is displaced by actuator 61.
In system 110, the temperature of the coolant within the first
fluid circulation loop 20 is monitored by a coolant temperature
sensor 62, which transmits a signal to electronic controller 60,
the controller 60 then controlling the actuator 61 which causes
displacement of the valve mechanism of valve 82B.
Similarly, the thermally actuated three-port second valve 82A of
system 100 may be replaced by a three-port electronically actuated
proportional second valve 82 which is adapted to control the output
of hot coolant from engine 12 to first heat exchanger 26 and to the
first valve 42/second heat exchanger 28. It will be appreciated
that it is not necessary that both the first and second valves in
system 110 are electrically actuated. Rather, one or both of these
valves may be thermally actuated, as in valves 42, 82 and 82A of
systems 10 and 100.
In embodiments where the second valves 82 described herein are
electronically actuated, as with second valve 82B of FIG. 9, it
will be appreciated that the second valve 82 does not necessarily
include a leak path 78 or 90 as described above. Rather, depending
on the temperature of the coolant sensed by a temperature sensor,
such as sensor 62 in FIG. 9, an electronically actuated valve 82
may be opened by a small amount, so as to provide the same volume
of coolant flow as leak paths 78 and/or 90. It will be appreciated
that any of the thermally actuated second valves 82, 82A described
above may be replaced by an electronically actuated valve such as
second valve 82B, which may or may not include a leak path 78
and/or 90.
FIG. 10 illustrates a heating/cooling system 120 according to a
fourth embodiment, in which like elements are identified by like
reference numerals. System 120 includes a second fluid circulation
loop 15 (shown in dotted lines) for circulating transmission fluid,
and a first fluid circulation loop 20 includes a high temperature
coolant circulation loop 20A and a low temperature coolant
circulation loop 20B. The high temperature coolant loop 20A has a
similar configuration to the first fluid circulation loop 20 of
systems 10, 100 and 110, including a high temperature radiator
which may correspond to the third heat exchanger of systems 10, 100
and 110, and is therefore labelled 24. In addition, the high
temperature coolant loop 20A includes an internal combustion engine
12 and a first heat exchanger 26 to heat air for the passenger
compartment 14.
The low temperature loop 20B circulates coolant at a lower
temperature than high temperature loop 20A. Low temperature loop
20B includes a low temperature heat exchanger 126, such as a low
temperature radiator, which is optional; and one or more low
temperature components 128 to which the coolant in loop 20B is
supplied. The coolant in low temperature loop 20B may be the same
coolant circulating in the high temperature loop 20A, and flows
through a coolant conduit 122 from the low temperature heat
exchanger 126 to the low temperature component(s) 128, with the
branch point between coolant conduit 122 and coolant conduit 40
being located downstream of the low temperature heat exchanger 126
and upstream of the low temperature component(s) 128, to receive
the cooled coolant discharged by heat exchanger 126. Once it is
heated by component(s) 128, the coolant returns to the low
temperature heat exchanger 126 through coolant conduit 124.
Also shown in FIG. 10 are overflow coolant reservoirs 132, 134 for
the respective high and low temperature coolant loops 20A, 20B. As
signified by dotted lines in FIG. 10, the overflow coolant
reservoirs 132, 134 are in fluid communication with one another and
with a main overflow coolant reservoir 136 which is also in fluid
communication with the high and low temperature heat exchangers 24,
126.
The system 120 of FIG. 10 also includes a dual mixing valve and a
transmission heater/cooler. The dual mixing valve is labeled 42 and
may be a thermally or electrically actuated three-port valve which
is identical to any of the first valves described above with
reference to systems 10, 100 and 110, including first valves 42 and
42A. The transmission heater/cooler is labeled 28 and may be
identical to the second heat exchanger 28 described above. As with
the first valves 42 and 42A described above, the dual mixing valve
42 of FIG. 10 permits selection between the hot and cold sources of
coolant, and the coolant inlet ports 50, 52, coolant conduits 38,
40, coolant outlet port 54 and coolant conduit 36 are labeled in
FIG. 10 to show similarities to the systems described above.
As with the embodiments described above, there may be a minor,
predetermined amount of coolant flow or "leakage" through the
two-port valve 82 in its first, closed position. This ensures that
the flow of heated coolant to the high temperature components 122,
including first heat exchanger 26, is prioritized over AWU (heating
of the transmission fluid), and that the hot coolant will prime the
AWU system by providing a limited amount of transmission fluid
warming. Also, where the two-port valve 82 is thermally actuated,
the leakage will ensure that the thermal actuator of valve 82 will
be maintained in contact with the stream of hot coolant from loop
20A.
The coolant discharged by the second heat exchanger 28 may be
directed to either the high or low temperature loop 20A or 20B,
depending on the temperature of the coolant at the outlet of the
heat exchanger 28.
Like systems 10, 100 and 110 described above, the system 120 has
three operating states. In a first operating state, corresponding
to cold start-up, the first valve 42 and second valve 82 are in
their first valve positions, i.e. the first valve 42 has first
inlet port 50 open, second inlet port 52 closed, and outlet port 54
open; and the second valve 82 is closed, optionally with a minor
amount of leakage through first second valve 82B, which may or may
not include a leak path 78 and/or 90 to prime the AWU system.
Therefore, in the first operating state, heating and/or defrosting
of the passenger compartment 14 is prioritized over active
warm-up.
In the second operating state, corresponding to warm-up, the first
valve 42 remains in its first valve position and the second valve
82 is in its second valve position, i.e. the second valve 82 is
open to permit the flow of coolant from the high temperature loop
20A to enter the first inlet port 50 of first valve 42, pass
through radial flow path 80 of valve mechanism 56, exit through the
outlet port 54, and flow through the second heat exchanger 28 to
heat the transmission fluid in second circulation loop 15. In the
second operating state, coolant will continue to flow through the
first heat exchanger 26. Therefore the second operating state
provides increased active warm-up of the transmission fluid and
continued heating and/or defrosting of the passenger compartment
14.
In the third operating state, corresponding to normal operation,
the first valve 42 adopts its second valve position and the second
valve 82 remains in its second valve position, i.e. the first valve
42 and second valve 82 are in their second valve positions, i.e.
the first valve 42 has first inlet port 50 closed, second inlet
port 52 open, and outlet port 54 open; and the second valve 82 is
open. Therefore, in the third operating state, the closed first
inlet port 50 prevents coolant from high temperature loop 20A from
flowing through first valve 42 to second heat exchanger 28, while
the open second inlet port 52 permits coolant from the low
temperature loop 20B to enter the second valve chamber 48 of first
valve 42 through open second inlet port 52. The coolant is then
discharged from outlet port 54 and flows through the second heat
exchanger 28 to cool the transmission fluid in the second
circulation loop 15.
FIG. 11 illustrates a heating/cooling system 140 according to a
fifth embodiment which is similar to the system 120 of FIG. 10, and
in which like elements are identified with like reference
numerals.
System 140 differs from system 120 in that the two-port valve 82 of
FIG. 10 is replaced by a three-port thermally or electrically
actuated valve which is similar in structure and function to second
valve 82A described above, and/or its electrically actuated
counterpart also described above. The second valve 82A has an inlet
port 84, a first outlet port 86 and a second outlet port 142. Due
to these similarities, the three-port valve is labeled 82A in FIG.
11. The other elements of system 120 are also present in system 140
and a detailed discussion of these elements is therefore
omitted.
Like the other systems described above, the system 140 has three
operating states. In the first operating state, at cold start-up,
the first and second valves 42, 82A are in their first valve
positions. The first valve position of the first valve 42 is the
same as described above, i.e. with first inlet port 50 open, second
inlet port 52 closed and outlet port 54 open. In its first valve
position, the three-port valve 82A blocks most or all of the flow
of hot coolant from high temperature loop 20A to the dual mixing
valve 42, in the manner described above with reference to other
systems 10, 100, 110, optionally with a minor portion of leakage
flow through second valve 82A. In this operating state, a major
portion of the hot coolant flow in coolant conduit 22 flows through
the first heat exchanger 26, with the major and minor portions of
coolant flow being the same as, or similar to, the minor and major
portions of coolant flow described above with reference to the
first operating state of system 10, shown in FIG. 2. This
prioritizes heating of the passenger compartment 14 by first heat
exchanger 26, optionally with a small amount of heating of the
transmission fluid in the second circulation loop 15.
As the temperature of the coolant in high temperature loop 20A
increases, the system 140 adopts its second operating state during
warm-up, with the first valve 42 remaining in its first valve
position and three-port second valve 82A adopting its second valve
position in which the coolant from high temperature loop 20A is
permitted to flow through the second valve 82A from inlet port 84
to first outlet port 86, entering the dual mixing valve 42 and
flowing to the heat exchanger 28 to heat the transmission fluid
circulating therethrough. In the second operating state, a major
portion of the coolant in high temperature loop 20A continues to
circulate through the first heat exchanger 26 to provide heating
and/or defrosting of the passenger compartment 14, and a minor
portion of the coolant in high temperature loop 20A flows through
second valve 82A, through first valve 42, and to second heat
exchanger 28. In the second operating state of system 140, the
major and minor portions of flow may be the same as, or similar to,
the major and minor portions of flow in the second operating state
of system 10.
As the temperature of the coolant in high temperature loop 20A
increases to normal operating temperatures, the system 140 adopts
its third operating state, with the first valve 42 adopting its
second valve position and the three-port second valve 82A remaining
in its second valve position. In its second valve position, the
first valve 42 has first inlet port 50 closed, second inlet port 52
open, and outlet port 54 open. Therefore, in the third operating
state, the closed first inlet port 50 prevents coolant from high
temperature loop 20A from flowing through first valve 42 to second
heat exchanger 28, while the open second inlet port 52 permits
coolant from the low temperature loop 20B to enter the second valve
chamber 48 of first valve 42 through open second inlet port 52. The
coolant is then discharged from outlet port 54 and flows through
the second heat exchanger 28 to cool the transmission fluid in the
second circulation loop 15.
The second outlet port 142 is connected to the first end of a first
bypass conduit 138, the second end of which is connected to
conduits 37 and/or 70, downstream of the first heat exchanger 26.
Therefore, the first bypass conduit 138 permits the flow of coolant
from the engine 12 and conduit 22 to bypass the first heat
exchanger 26. Such a bypass 138 may be used under extreme cold
start conditions, for example of temperatures on the order of
-20.degree. C. and below. Under extreme cold start conditions, the
use of first bypass conduit 138 allows engine heating to be
prioritized immediately after the engine is started. Thus, system
140 effectively has a fourth operating state under extreme cold
start conditions. In this operating state, a flow path from inlet
port 84 to second outlet port 142 is completely open to permit a
major portion of the coolant in conduit 22 to enter conduit 38 and
flow through second valve 82A. The flow path from inlet port 84
through outlet port 86 may either comprise a leak path as in the
first operating state, or it may be completely closed such that no
coolant reaches the second heat exchanger 28 in the fourth
operating state.
The fourth operating state will remain in effect for a
predetermined period of time to permit some warming of the engine
12 to occur, typically less than about 30 seconds. During the
fourth operating state, the volume of coolant flow through the
first bypass conduit 138 will be on the order of about 90% by
volume of the total coolant flow from engine 12 through coolant
conduit 22. The control of the flow path from inlet port 84 to
second outlet port 142 may be electronically controlled, for
example in response to a temperature sensor (not shown) located in
coolant conduit 22. Also, as shown in FIG. 11, there may be a
second bypass conduit 144 to optionally bypass the third heat
exchanger 24, for example during the fourth operating state. Once
sufficient engine heating has taken place, the second valve 82A
will close the first bypass conduit 138 and the system 140 will
adopt the first operating state. Optionally, flow through the first
bypass conduit 138 may resume under other operating conditions, for
example during operating conditions where heating of air by first
heat exchanger 26 is not required.
Although not shown in FIGS. 10 and 11, it will be appreciated that
the high temperature coolant circulation loop 20A of systems 120,
140 may include a bypass passage 23 similar to that described
above, controlled by a bypass valve, through which the coolant
circulating in the high temperature loop 20A may bypass the first
heat exchanger 26 and flow directly to the heat exchanger 24.
While various valve system configurations have been described in
connection with the present disclosure, it will be understood that
certain adaptations and modifications of the described exemplary
embodiments can be made as construed within the scope of the
present disclosure. Therefore, the above discussed embodiments are
considered to be illustrative and not restrictive.
* * * * *